1. Field of the Invention
This invention relates to a concrete pump apparatus and more particularly to a concrete pump apparatus which is mounted on a truck crane.
2. Description of the Related Art
Concrete is sometimes pumped to locations where it is difficult or impossible for a concrete mixer truck to gain access thereto. Such is the case where concrete is to be poured behind a house or the like where it is impossible to drive the concrete mixer truck. One alternative to such a situation is to use wheelbarrows to transport the concrete to the location where it is to be placed. Another solution has been to utilize a telescoping or articulated boom assembly which is mounted on a truck. In some cases, a concrete pump is positioned on the truck and a concrete conduit, such as a flexible hose, is extended from the pump, along the length of the telescoping boom, at the exterior surface thereof, to a discharge conduit from which the concrete is discharged. The telescoping boom is extended and maneuvered to position the discharge conduit at the proper location. Although concrete pumpers of the type described do work quite satisfactorily, the boom assemblies thereof have no use other than for pumping concrete. In other words, the boom assembly cannot be used as a crane during those times when concrete is not being pumped. If the boom assembly does not have an aerial platform thereon, it is impossible for an operator to be therein for pumping and spraying concrete. Usually, the spraying of concrete is called shotcrete. Shotcrete is the spraying of concrete on wire mesh for texturing surfaces similar to stucco. If one does not have an aerial lift, then the person must walk on scaffolding and manhandle the hose to shotcrete. To the best of applicants' knowledge, the invention disclosed in the parent application, Ser. No. 09/548,103, is the only aerial lift unit that allows a person to pump concrete from the aerial platform.
In the above-identified parent patent application, a flexible hose extends between the discharge side of the concrete pump and the rearward end of the concrete conduit positioned within the telescopic boom assembly. The flexible hose is coiled on the crane platform when not in use. As the telescopic boom is extended, the flexible hose is pulled from the coil into the interior of the boom assembly. When the boom assembly is retracted, it is necessary to pull the hose rearwardly from the interior of the boom assembly and position the same on the crane platform. Although the apparatus disclosed in the above-identified application performs exceptionally well, the instant invention overcomes the need to coil the flexible hose on the crane platform.